The present invention is directed generally to hearing aids. More specifically, the invention is directed to a contact arrangement for electrically connecting a battery power supply to electrical components of the hearing aid. Yet more specifically, the invention is directed to a spring contact arrangement wherein the battery power supply is carried in a compartment which is pivotally attached to the hearing aid housing and wherein pivoting of the compartment places the battery into contact with spring contacts to thereby provide electrical power to the electrical components of the hearing aid and to thereby turn on the hearing aid.
Due to space requirements, the turn on and turn off of known hearing aids, for example, the hearing aid disclosed in West German application No. DE-AS 25 03 253, frequently is accomplished not by means of a separately provided switch, but by means of a pivoting battery compartment. In No. DE-AS 25 03 253, a hearing aid assembly comprises a battery holder rotatably mounted about an axis perpendicular to a junction plane of halves of the housing. Two contacts are integrated in the housing in registry with the battery compartment so that as the battery compartment is pivoted, very much like a knife switch, the contacts contact a battery in the compartment on opposite sides of the battery, usually only when the battery is fully pivoted into the hearing aid housing. The battery is tablet-shaped with its poles located on opposite sides of the battery, or with the casing constituting one pole while one face constitutes another pole. The battery compartment includes a cylindrical bore into which the battery is positioned. The spring contacts are located on opposite sides of the battery compartment on walls of the housing so that the battery compartment and, accordingly, the battery, pivots between the spring contacts.
In a first position (the "on" position), when the battery is fully pivoted into the hearing aid housing, the hearing aid is switched on and the electrical components thereof are supplied with power and, accordingly, lie at voltage. In a second position (the "off" position), when the battery is partially pivoted out of the hearing aid housing, the battery contacts only one contact spring but the battery cannot be removed and cannot fall out of the battery compartment, since the battery compartment projects only partially out of the house. This second position is the "off" position because the electrical components of the housing are decoupled from the battery power supply. However, with certain unfavorable tilting of the battery, for example, if the battery is in a tilted position within the battery compartment, undesired contact in between the battery and the two spring contacts can occur. In a third position (the "change battery" position), the battery compartment is fully pivoted out from the hearing aid housing. In this position of the battery compartment, a battery can be removed from or inserted into the battery compartment.